JPS6248816B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color light modulation device used in color printers, color facsimiles, color display devices, and the like. More specifically, the present invention uses a monochrome cathode ray tube (CRT) to transmit light from the CRT through an optical filter that can change the wavelength region of the light that passes through it by controlling the applied voltage. For example, the present invention relates to a color light modulation device that can irradiate a photosensitive means and obtain a color image on the photosensitive means.

Conventionally, devices for obtaining color images have used red (R), green (G), and blue (B) color CRTs, but this requires three drive circuits and is complicated. , R, G, and B and the position adjustment is not performed accurately, there are drawbacks such as color misalignment and decreased resolution.

An object of the present invention is to realize a color light modulation device that has a simple overall configuration, can be constructed at low cost, has high resolution, and does not cause color shift.

A color light modulation device according to the present invention includes a monochrome cathode ray display tube, an electro-optic material substrate through which light from the monochrome cathode ray display tube passes, an electrode provided between the electro-optic material substrate, and an electric current transmitted through the electrode. A drive circuit including a variable power source that applies a voltage to the optical material substrate, a color photosensitive means to which light emitted from the electro-optic material substrate is irradiated, and a color specification device that applies the voltage applied to the electro-optic material substrate to the drive circuit. It is characterized in that a color image (including a positive line and a negative latent image) is obtained on a color photosensitive means by controlling the voltage to a predetermined voltage according to a signal.

FIG. 1 is a block diagram showing one embodiment of the present invention, and here an example of a color printer is shown.

In the figure, numeral 1 is a monochrome cathode ray display tube (hereinafter referred to as CRT) with a one-dimensional line-shaped display surface, and a phosphor that emits light when exposed to electron beams is installed on the display surface. 2 is a fiber plate that guides the light spot on the CRT display surface, and 3 is a deflection coil that deflects the electron beam. Here, it is possible to use a monochrome fiber optic tube (FOT) as a CRT in which the fiber board 2 is installed on the display surface. Note that the fiber plate 2 is not necessarily required. 4 is an optical filter on which the light spot of the CRT display surface enters; 5
is a drive circuit for the optical filter 4, to which a color designation signal is given from the control circuit 6, and a predetermined voltage corresponding to the color designation signal is applied to the optical filter 4. Reference numeral 7 denotes a self-occurring lens, which serves to focus the light emitted from the optical filter 4 into a beam. Note that this self-cleanse is not necessarily required. Reference numeral 8 denotes a color photosensitive drum, which rotates at a constant speed, and is irradiated with light emitted from the self-occurring lens 7. Note that instead of the color photosensitive drum, color photosensitive paper or a color display surface may be installed here. Note that 60 is a temperature detection means for detecting the temperature of the optical filter 4, which is provided as necessary to eliminate the influence of the temperature of the optical filter 4, and its output signal is applied to the control circuit 6. , controls the driving voltage. In order to eliminate the influence of the temperature of the optical filter 4, in addition to this, for example, a part of the output light of the optical filter is detected by a photodiode, and the temperature is corrected by feedback control using the control circuit 6. You can do it like this.

FIG. 2 is a perspective view showing an example of the optical filter 4 used in the device shown in FIG. In the figure, 41 is a plate-shaped electro-optic material substrate having an electro-optic effect such as the Kerr effect. This material substrate includes PLZT, LiNbo ₃ ,
BSO etc. can be used, but PLZT has a larger electro-optic constant than other materials, requires a lower driving voltage, and has a transmission wavelength range of 0.4 μm to 8 μm.
It is the most suitable because it operates not only in visible light but also in the far infrared region. 42 and 43 are Cr provided on the surface of the electro-optic material substrate 41 so as to sandwich it;
The electrode is made of Au or the like and is formed on the substrate 41 using a technique such as vapor deposition or sputtering.
The drive circuit 5 is connected to the electrodes 42 and 43,
A predetermined voltage is applied to the electro-optic material substrate 41 via this electrode. 45 and 46 are electro-optic material substrates 4
1 and placed in the path of light passing through the optical material substrate 41, the plane of polarization of the polarizer 45 on the side where the light enters and the polarizer 46 on the side from which the light exits are as follows. An example (an example of orthogonal polarizers) in which the polarizers are arranged at 45 degrees with the direction of the electric field in the optical material substrate 41 (direction perpendicular to the electrode surface) and perpendicular to each other is shown. Note that the polarization planes of the polarizers 45 and 46 may be arranged parallel to each other (parallel polarizers),
Furthermore, depending on the shape of the electro-optic material substrate, these polarizers 45 and 46 are not necessarily required.

In the optical filter configured in this manner, a PLZT substrate is used as the electro-optic material substrate 41, and when a voltage is applied to the electro-optic material substrate 41 via the electrode, this is caused by the electric field generated in the material substrate. The operation will be explained based on the assumption that the property (Kerr effect) in which a phase difference occurs between the polarized light component perpendicular to the electric field and the light polarized light component parallel to the electric field is used.

Now, in FIG. 2, when non-monochromatic light (multi-wavelength light flux) is incident on the optical material substrate 41 from the polarizer 45 side, this incident light
Due to the Kerr effect, a phase difference occurs between the polarized light component perpendicular to the electric field and the light polarized light component parallel to the electric field, which passes through the polarizer 46 and becomes emitted light.

Here, assuming that there is no loss due to the optical material substrate 41, the ratio (light transmittance) between the incident light Ii and the output light Io to the electro-optic material substrate that has passed through the polarizer is as follows.
It can be expressed by the following equation.

In the case of orthogonal polarizers: Io/Ii=Sin ² (πn ³・R・L/2iD ²・V ₂
)...(1) For parallel polarizer: Io/Ii=Cos ² (πn ³・R・L/2iD ²・V ₂
)...(2) However, n: refractive index R: Kerr constant V: applied voltage λ: wavelength of light D: inter-electrode spacing L: optical path length in the electro-optic material substrate Figure 3 shows that in Figure 2, FIG. 4 is a characteristic diagram in which the relationship between the voltage applied between the electrodes 42 and 43 and the light transmittance Io/Ii was investigated by changing the wavelength of incident light. Here, n=2.5, R=3.0x10 ^-16
m ² /V ² , D=380 μm, and L=5 mm. From this experimental result, when the applied voltage is 50V or less, each wavelength of light exhibits almost the same transmittance characteristics, but when the applied voltage exceeds 90V, each wavelength exhibits different transmittance characteristics. It has been recognized that it can last a long time.

FIG. 4 is a characteristic diagram showing the relationship between the wavelength of transmitted light and the light transmittance using the applied voltage as a parameter. Here, the applied voltage is 90V, 100V, 110V
The experimental results showed that by controlling the applied voltage, the wavelength region of light passing through could be changed. In other words, at an applied voltage of 90V, the wavelength is 440n.
With an applied voltage of 100 V, specific light with a wavelength of about 550 nm can be passed, and with an applied voltage of 110 V, specific light with a wavelength of about 650 nm can be passed. Therefore, in FIG. 2, by changing the value of the voltage V applied between the electrodes 42 and 43, the wavelength range of the light passing through can be arbitrarily set.

FIG. 5 is a characteristic diagram showing the voltage dependence of the hue of the exit hole on a chromaticity diagram in the optical filter of FIG. 2. Here, the applied voltage V was gradually increased from 40 V to 160 V, and as is clear from this diagram, by setting the applied voltage V to an arbitrary value, the hue of the emitted light can be changed. can be set within a predetermined range.

Further, if the pulse width (time width) of the applied voltage is controlled at a predetermined voltage, the amount of light passing through the device changes over a certain period of time, and the brightness (brightness and darkness) can also be controlled.

Returning to FIG. 1, an example of the operation will now be described with reference to the waveform diagram of FIG. 6.

The drive circuit 5 includes, for example, a ROM (read-only memory), and the most appropriate voltage signals corresponding to each hue of light emitted from the optical filter 4 are stored in advance. this
Storage in the ROM is performed, for example, in accordance with a characteristic line showing voltage dependence expressed on a chromaticity diagram as shown in Fig. 5. Within the range of the moving point, a plurality of various hues can be arbitrarily set by using a predetermined voltage.

The drive circuit 5 is given a color designation signal from the control circuit 6, and applies a predetermined voltage to the optical filter 4 according to the color designation signal. In other words, when using an optical filter with voltage dependence as shown in Figure 5, in the case of white,
It outputs a voltage of 50V for T hours, and when it is red it outputs a voltage of 75V for T hours, and when it is green, it outputs a voltage of 75V for T hours.
A voltage of 125 V is output for a time T and is applied to the electro-optic material substrate 41 of the optical filter 4 as shown in FIG.

Further, a brightness signal is also given to the drive circuit 5, and by controlling the time during which the voltage of a predetermined magnitude is applied according to the brightness signal, the transmittance of light is changed together with the color, and the brightness is changed. That's what I do. For example, if the color is blue and has a dark brightness, a voltage of 90 V is applied for t ₁ time (t ₁ <T) as shown in FIG.

In this way, the hue and brightness of the light from the display surface of the monochrome CRT 1 that passes through the optical filter 4 are controlled by the magnitude and application time of the applied voltage, which causes the self-cleaning lens 7 to As a result, the light is irradiated onto the photosensitive drum 8, which is a color photosensitive means, and a color image or a color latent image can be obtained thereon.

FIG. 7 is a block diagram showing another embodiment of the apparatus according to the present invention, in which a case where color photosensitive paper is used as the color photoreceptor is illustrated.

In this embodiment, a monochrome CRT 1 with a two-dimensional display surface is used, and
A plurality of (two examples are shown here) electro-optic material substrates 41a are provided with optical filters 4 in the direction of light propagation.
41b and these monochrome CRTs.
A large number of optical material substrates 45, 46, 47 are laminated in correspondence to the number of rasters on the display surface 1, and polarizers 45, 46, 47 are arranged so that the plane of polarization is parallel to each optical material substrate 41a, 41b and to the incident and exit surfaces of the light, respectively. It is arranged and configured. Each optical material substrate 41a, 41b includes
Predetermined voltage that changes in response to color specification signal
Va and Vb are applied. Here, predetermined voltages Va, Vb applied to each electro-optic material substrate 41a, 41b
The ratio (Va/Vb) is maintained at a constant ratio as described below.

The operation of the apparatus configured as described above will be explained below, focusing mainly on the operation of the optical filter 4.

Figure 8 shows an optical filter with a parallel polarizer configuration consisting of one electro-optic material substrate, with the voltage applied to the electro-optic material substrate being 106V (solid line),
It is a characteristic diagram examining the relationship between the wavelength of passing light and light transmittance when the voltage is 150V (broken line). When two optical filters with such characteristics are arranged one on top of the other, the overall optical characteristics will be the product of the two characteristics.

The optical filter 4 used in the device shown in FIG.
106V), and when a voltage (for example, 150V) is applied to the second electro-optic material substrate 41b, the overall optical characteristics of the optical filter 4 become narrower, as shown in FIG. 9, and the separation characteristics are improved. It becomes what it is. In this characteristic diagram, each voltage Va, Vb is
When the voltage is changed, the center wavelength of the bandwidth shifts in parallel in the characteristic diagram in FIG. can do.

This driving method uses an applied voltage that matches the transmission characteristics of each of the two optical filters with the desired wavelength (bandpass filter), but as another example of driving, one optical filter can be moved to the desired wavelength band. A pass filter may be used, and another optical filter may be operated as a band reject filter that removes side bands of the band pass filter. In this case, the applied voltages Va and Vb corresponding to each hue are, for example,
It is stored in ROM and read out sequentially.

Returning to FIG. 7, the monochrome CRT 1 displays an image similar to that of a normal mole-color television on its display surface. The light from this monochrome CRT 1 enters an optical filter 4 constructed of laminated layers, where it becomes color light of a predetermined color, and is irradiated onto a color photoreceptor 8 through a self-occurring lens 7. Therefore,
A monochrome image appearing on the display surface of the monochrome CRT 1 can be displayed on the color photoreceptor 8 as a color image.

In each of the above embodiments, the drive circuit 5 and the control circuit 6 are conceptually shown as separate blocks, and the control circuit 6 provides the drive circuit 5 with a color designation signal and a brightness designation signal. , and both circuits may be constituted by, for example, a microprocessor including a memory circuit, and in this case, they can be represented by one block.

As explained in detail above, the device according to the present invention includes a monochrome cathode ray display tube with good resolution,
The light from this display tube enters, and the hue and brightness of the emitted light are controlled by the voltage magnitude and application time, and the light travels between the electrodes through an optical filter and an optical filter. The color light modulation device has a simple overall configuration, can be constructed at low cost, has high resolution, and can control brightness without causing color shift. can.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
The figure is a structural perspective view showing an example of the optical filter used in the device shown in Fig. 1, and Figs. Figure 4 is a diagram showing the relationship between applied voltage and light transmittance; Figure 4 is a diagram showing the relationship between wavelength of passing light and light transmittance using applied voltage as a parameter;
The figure is a line diagram showing the voltage dependence of the hue of the emitted light on a chromaticity diagram, FIG. 6 is a waveform diagram for explaining the operation of the device shown in FIG. 1, and FIG. 7 is a diagram showing other devices according to the present invention. FIGS. 8 and 9 are characteristic diagrams for explaining the operation of the optical filter used in the apparatus shown in FIG. 7. 1... Monochrome CRT, 2... Fiber board, 3
...Polarizing coil, 4...Optical filter, 5...Drive circuit, 6...Control circuit, 7...Self-occurrence lens, 8...Color photoreceptor.

Claims (1)

[Scope of Claims] 1. A monochrome cathode ray display tube, an electro-optic material substrate through which light from the cathode ray display tube passes, and electrodes provided on the electro-optic material substrate so as to be sandwiched from the thickness direction perpendicular to the direction in which the light travels. an optical filter configured to change the hue of the light according to a voltage applied to the electro-optic material substrate via the electrode; a color designation signal and a brightness signal are given; A color light modulation device comprising: a drive circuit that applies a voltage of a predetermined magnitude to an electrode of the optical filter for a time corresponding to the brightness signal; and a color photosensitive means to which color light emitted from the optical filter is irradiated. 2. The optical filter is constructed by arranging a plurality of electro-optic material substrates in the direction in which the light travels, and a voltage having a predetermined relationship is applied to each electro-optic material substrate in accordance with the brightness signal. 2. The color light modulation device according to claim 1, wherein the light is applied for only a certain period of time.