JPH0331353B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention provides Braille characters expressed by the number and arrangement of protrusions, and a target screen whose density distribution is expressed by a plurality of gradation levels, the size of which corresponds to the gradation levels. The present invention relates to a braille printing head of a braille printer that can selectively form both a dot image drawn by a protrusion having a dot and a dot image on braille paper. [Prior art and its problems] Braille consists of six combinations of three dots vertically and two dots horizontally, and is expressed by dots placed on Braille paper. It is also possible to use sets to draw regular characters or graphics on Braille paper, rather than Braille, so that blind people can recognize the characters or graphics. However, since characters or figures using such dots for Braille are expressed in two gradations, it is possible to express letters or simple figures, but it is impossible to express the shading and perspective of the image. It was hot. [Object of the Invention] Therefore, an object of the present invention is to provide a braille print head for a braille printer that can form dot images expressing shading and perspective on braille paper in addition to the normal braille forming function. shall be. [Summary of the Invention] Therefore, the braille printing head according to the present invention has the following features:
A predetermined number of dot pins for forming braille arranged in a predetermined alignment and having substantially the same size and the dot pins for forming braille are different in size, and together with at least one of the dot pins for forming braille, The apparatus is characterized in that it includes at least one dot image forming dot pin capable of forming the braille image. [Embodiments of the Invention] Embodiments of the present invention will be described in detail below with reference to the drawings. However, in order to facilitate understanding of the present invention, first, prior to explaining the braille printing head of the present invention, the object Let's explain a device that reads point images corresponding to the density distribution on the screen and converts them into digital codes. FIG. 1 is a block diagram of an image reading/reading device, in which 1 is an optical sensor that scans the target screen 2 and generates an analog signal representing the density distribution of the target screen;
3 is an A-D conversion circuit for converting this analog signal into a digital code, and 4 is for writing the digital code which is the output of this A-D conversion circuit 3 in an arrangement corresponding to the density distribution on the target screen 2. of
RAM, 5 is a CPU, and 6 is a Braille printer that prints dots on Braille paper 7. In addition, RAM4
When writing data to the Braille printer 6
It goes without saying that an image reading device separate from the Braille printer 6 may be used, in which the optical sensor 1 is attached to the Braille printer 6 and the Braille printer 6 is configured to operate as a device for reading the image of the target screen 2. 8 is an input device for inputting an operating program for the Braille printer 6, and 9 is a PROM into which the operating program is written. FIG. 2 is a circuit diagram of an image reading circuit including an A-D converter circuit 3. The A-D converter circuit 3 has three comparators 11, 12 and 13 to express the density of the target screen in four gradations. It is equipped with a parallel type A-D conversion circuit. Reference voltages V ₁ , V ₂ and V ₃ as threshold values of each comparator (however, V ₁ > V ₂ >
V ₃ ) are variable resistors VR ₁ , VR ₂ and
Given via VR ₃ . The optical sensor 1 is the light source 14
A phototransistor 15 scans the target screen 2 with the optical sensor 1 to generate an analog signal representing the density distribution of the target screen, and this analog signal is sent to each comparator 11, 12, and
is given as an input signal. The relationship between the reference voltages V ₁ , V ₂ and V ₃ of each comparator and the output voltage V _A of the optical sensor 1 and the binary output of each comparator 11, 12 and 13 at that time are shown in Figure 3 and below. Represented in a table.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in addition to forming normal Braille characters, for example, 4
It is now possible to draw point images expressed in gradation, and therefore the shadows and perspective of the image can also be expressed with salient points, greatly expanding the scope of use of this type of point image. can do. Further, according to the present invention, when forming a dot image, by using at least one of the dot pins for forming a dot image, the number of dot pins for forming a dot image plus two gradation levels is obtained. Since a dot image representing the density distribution of the screen can be displayed on Braille paper, there is an advantage that the number of dot pins used only for forming the dot image can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an apparatus to which a braille printing head according to the present invention is applied, FIG. 2 is a circuit diagram of an image reading circuit, FIG. 3 is a diagram showing the relationship between the reference voltage of a comparator and image density, and FIG. 4 is a front view of the head for braille printing according to the present invention, FIG. 5 is a plan view thereof, FIG. 6 is a side view thereof, FIG. 7 is a perspective view of the pin stand, and FIG. 8 is a head for braille printing according to the present invention. FIG. 9 is a plan view showing the arrangement of the dot pins of the head; FIG. 9 is a front view showing the Braille printing head according to the present invention with one pin holder removed; FIG. 10 is a perspective view of the tip of the hammer; FIG. 12 is a front view of the essential parts of the Braille printer, FIG. 12 is a plan view thereof, and FIG. 13 is a side sectional view thereof. In the drawing, 1 is a light sensor, 2 is a target screen,
3 is A-D conversion circuit, 4 is RAM, 5 is CPU, 6
is a Braille printer, 7 is a Braille paper, 8 is an input device,
9 is PROM, 11 to 13 are comparators, 14
is a light source, 15 is a phototransistor, 16 to 18
is a flip-flop, 19 is a pulse generator for writing, 20 is a push button switch for clearing, 21 is a liquid crystal numeric display, 23 is a control state bus,
30 is a braille print head, 31 and 32 are pin holders, 33 and 34 are shafts, 35 is a pin stand, 36,
36a, 36b, 36c are dot pins, 39 is an operating wire, 41 is a hammer, 44 is a carriage, 4
5 is a solenoid, 48, 49, 51 are rails, 5
0 and 53 indicate an endless belt, 52 a bearing, and 54 a hammer arm, respectively.

Claims (1)

[Scope of Claims] 1. Braille characters expressed by the number and arrangement of peak points, and peak points whose density distribution on the target screen is expressed by multiple levels of gradation and whose size corresponds to the gradation. A braille printer head for a braille printer capable of selectively forming both a dot image drawn by and at least one dot image forming dot that is different in size from the dot pin for forming braille and said dot pin for forming braille, and that can form said dot image together with at least one of said dot pins for forming braille. A braille printing head for a braille printer, characterized by having a pin and. 2. The dot pin for dot image formation is composed of two dot pins having two types of sizes, large and medium, which are larger than the dot for dot formation, and these two dot pins for dot image formation and the dot pin for forming the braille Pointing out projecting points having three types of sizes, large, medium, and small, on the Braille paper using at least one of the forming point pins,
2. The braille printing head according to claim 1, wherein the braille printing head is configured to form a dot image on the braille paper, which represents the density distribution of the target screen in four gradation levels.